Slightly South of Jekyll & Cumberland Isls is North Florida beginning with Fort Clinch (occupied by Union army during Civil War) along St Marys river - dividing line between FL & GA. Talbot Island has dynamic coastline with plenty of driftwood as an old oak forest is being eroded by the ocean. Timucuan preserve with thousands of acres of salt-water marsh. Guana River State Park & management area, 12,000 acres of barrier island that includes dunes, fresh & salt-water marsh and extensive live-oak forest. Nice thing about the area is that until you get down to St Augustine tourist crowds & commercialization are not problems.
Btw, State of Florida recently clarified their photography permit - only charged at State Parks if photographer requires disruption of park service, eg early closing for filming purposes.